Date: Tue, 4 May 1999 20:14:00 +0100 (BST) From: Doug Rabson <dfr@nlsystems.com> To: Tony Finch <fanf@demon.net> Cc: current@freebsd.org Subject: Re: NFS Patch #8 for current available - new TCP fixes Message-ID: <Pine.BSF.4.05.9905042013150.637-100000@herring.nlsystems.com> In-Reply-To: <E10efU7-0004Iv-00@fanf.noc.demon.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 4 May 1999, Tony Finch wrote: > Matthew Dillon <dillon@apollo.backplane.com> wrote: > > > > (fanfair!) > > :-) > > > NFS attempts to realign packet buffers and trods all over the underlying > > mbufs. For TCP connections, several RPC's may be present in an mbuf > > chain. The realignment of one of them may destroy the others. This does > > not occur with UDP because each UDP packet contains only a single rpc. > > > > Packet buffers may be unaligned for a number of reasons. The main reason > > is due to the 14 byte MAC header on the ethernet frame. This causes the > > remainder of the packet - the ip payload - to NOT be 4-byte aligned. > > We're planning to try replacing some Solaris web servers with FreeBSD > machines in the near future. The documents are on a read-only NFS > filestore connected to the web servers with CDDI. (Updates will stay > on a Sun box.) Are we going to have nfs_realign problems if we use TCP > in this situation or should we stick with UDP? I think UDP will probably work better. There won't be any problem with frames being re-ordered and the protocol overhead should be less. -- Doug Rabson Mail: dfr@nlsystems.com Nonlinear Systems Ltd. Phone: +44 181 442 9037 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.BSF.4.05.9905042013150.637-100000>